Only a day left to register…
SSWUG SharePoint Expo – May 28th
The May SharePoint Expo from SSWUG.ORG is a free event, open to all. The expo will include sessions on SharePoint from top-name presenters. These are encore presentations of top-rated sessions from the Virtual Conference – released to the community during this expo event. Available for 7 days beginning Friday, May 28th at 9am PST.
Sign up today. <- click to register…
Featured Article(s)
Troubleshooting SQL Server 2008 Query Notifications
In this article, Alexander Chigrik describes some problems you can have with SQL Server 2008 query notifications.
Open Question – Can You Help?
http://bitonthewire.wpengine.com/forums/tm.aspx?m=7894 – Has anyone attemted to upgrade multiple instances from SQL 2008 to SQL 2008R2? Here is what I’ve attempted. The components all get upgraded, but not the instances.
Setup.exe /q /ACTION=UPGRADE /INSTANCEID="INS01" "INS02" "INS03" INSTANCENAME="INS01" "INS02" "INS03" /IACCEPTSQLSERVERLICENSETERMS
What am I missing here? Has to be something simple.
Compression, Data Deduplication and Storage Management
Of course it’s never as easy as just "do this, then that happens." There are so many variables in what we do with our SQL Servers. I wrote yesterday about the combination of options available, from compression to deduplication , when it comes to managing storage requirements. I had a good exchange today with Jonathan that highlighted now only technology that might not combine how you think it might but even the terminology issues involved…
From Jonathan – "The proposed multipronged approach in today’s newsletter won’t work the way you might think. Compressed and encrypted files don’t generally allow deduplication to work because the blocks don’t match between the files. For example, a compressed SQL Server Backup removes the redundancy to minimize the file size. The blocks written out are different from full backup to full backup depending on the changes in the data that have occured. For this reason, most of the deduplication appliance vendors recommend against compressing things like SQL Backups because it removes the effectiveness of the deduplication and compression of the appliance."
A couple of things to get from this. First, deduplication is interesting in this context because I was actually talking about a different application of it than Jonathan is, but it’s the same term and so close in meaning that it’s easy to get tripped up. Deduplication in terms of what I was talking about was more about literally not having duplicate data (multiple copies of rows, multiple copies of data, etc.). Essentially, reviewing normalization, how you store information, literally having multiple copies. What these applications, compression routines and appliances do is to look at data and then apply deduplication and actually store and process data differently to optimize it.
It’s very true that if you are applying both compression at the "client" (SQL Server) side AND at the appliance side, you can really impact the ability of the appliance to do its job. Furhter, encryption can impact these appliances and some "outside the SQL Server process" routines for compression too. Since you’re encrypting data, you introduce more random noise, making compression and deduplication much more difficult or nearly impossible. You can see compression rates drop to nearly worthless values when you’re encrypting and compressing data in these types of situations.
Long story short – make sure you’re talking apples and apples first. Make sure when you talk with vendors that you understand how their tool handles encryption, data compression and so-on. Make sure it doesn’t conflict with your storage approaches for the database when you’re looking at the storage approach for backups and on-disk storage. It’s a bit like compressing a .ZIP file. You get to the point where compression can’t compress compression effectively. Sounds odd, but I hope it makes sense.
More tomorrow on this – doing more research on different options and such – had a few feedback items from readers that seemed to conflict, so I need to do more reading up on this.
Have experience with this? Email me, let me know what you’ve seen.